Method and apparatus for making a polygonal foam block of bonded foam pieces

The invention relates to a method and apparatus for producing Foam blocks with a square cross-section in the flock composite, wherein foam flakes charged into a flask with adjoining mold walls be and the filling then desired the means of a punch Density or block level is compressed and the finished block is removed from the mold after.

The production of composite blocks of rectangular section of foam flakes, For example, polyurethane foam flakes, after the above Method is generally known. The flakes are a sprayed binder or sintered together or fused. Depending on the type the Füllquerschnitts the selected mold box, the manufactured blocks adjacent the round block shape on generally rectangular or square cross-section; they but can also have a different polygonal shape.

While round blocks over the filling cross-section homogeneous density distribution is achievable, it is disadvantageous in square Füllquerschnitten that when Block manufacture, particularly as a function of the floc size and the Orientation of the flakes to form bridges, during filling of the flakes in the Flask especially in the corners of cavities and rounded form, wherein Also in these areas has a lower density than is produced inside the block. In particular, the processing of flakes in the usual sizes 12-15 mm prepares the said difficulties.

Because the cavities and rounded corners, and the inhomogeneous density - Seen across the block cross section - was already tried by hand in flakes the corners nachzustopfen. This means a higher cost in the Production, and thus achieved in the corners density depends solely on the skill of Operator, and is not reproducible.

For the use of the block material for articles upscale claims it is therefore often necessary to square the finished flock composite block to prune to eliminate non-circular edges and corners inhomogeneous. By However, this measure creates about 10% of waste, for which the Production work is lost, even if this waste is generally for can recycle inferior qualities.

There is therefore the task of angular foam composite blocks by compacting the flake material with creating edges and homogeneous density distribution produce over the entire cross section block.

This object is achieved in that before filling the plastic foam flocks the cross-section in every corner formed by two mold walls at a filling cross-section is extended, and that the after filling of the plastic foam flocks filling cross-section to be produced to the desired shape of the cross-section of the will block reduced, and that only after the fill to the desired density or block level is compressed.

By this measure it is achieved that the entire manufactured flock composite block even at elevated quality standards, in particular because of its homogeneous density distribution and fully filled corners, is usable. waste was not formed. Also Nachstopfen by hand is not required. It is understood without saying that the enlargement and reduction of the filling cross-section on the must be entire height of the flask and the filling height.

In practice, it is in the production of such blocks to mostly rectangular, in particular square. But the new invention can be in the production Apply all square blocks. The more corners of the block has, the is lower at its conventional preparation, the risk of inhomogeneity of the Density and unfilled corners. Ie, on the other hand, that in the preparation of quadrangular or merely triangular blocks the application of the new method is particularly advantageous.

The new apparatus for producing foam blocks with square cross-section the flock composite process starts from a flask with a Ground and standing on it more, contiguous form walls and a movable towards the bottom punch.

The new is the fact that through at any two adjacent Mold walls formed a corner of the mold walls is divided into a fixed wall part and it held about a vertical pivot axis movable flap, movable between a position pointing outwards and a fixed with the is pivotable wall part parallel position.

This ensures that prior to filling the filling cross-section through after-outer-panning the movable flap in the corners is increased and that this Position is maintained during the filling with the flakes. With the completion of the Filling the flaps are moved inwardly whereby the flakes from be supplanted these extended areas inward so that previously may existing cavities disappear and the lower density per se in this Areas is increased to the normal level. The size of the required extension the filling cross-section and the associated required opening angle of the flaps and their width can be, depending on the properties best identify the flakes empirically.

Preferably, each bearing against a flap mold wall has in the region the pivoting angle α of the flap an angle α corresponding this pivot Curvature.

This embodiment is particularly advantageous because then the filling of the Flakes into the molding box with outwardly pivoted flaps always a seal the adjacent mold wall is such that no flakes emerge can. This seal is also during retraction of the flaps in their final position receive.

Preferably, the flaps with a hydraulic device can be actuated.

This can advantageously be the necessary pressure force for moving the flaps muster. A manual operation with locking etc. would also be possible, but is very time consuming and labor intensive.

In conventional per se and advantageously, the new device is a Control unit equipped, so that the manufacturing processes substantially automatically or run semi-automatically. This controller acts according to the Stamp and the hydraulic devices of the flaps and the emptying process on.

The emptying of the device is performed in a conventional manner by pulling the correspondingly designed mold box and pushing away the finished Block or by folding of the form walls and removing the block. In any event, the mark must be returned before emptying.

It is understood that the molding box preferably in a conventional manner having rectangular or square cross-section.

In the drawing, the new device is shown purely schematically and below described in detail. Show it:<dl tsize="7" compact="compact"><dt>Fig. 1</dt><dd>the device with easy-filled mold box in cross section,</dd><dt>FIG. 2</dt><dd>the detail A of FIG. 1 in an enlarged representation and </dd><dt>FIG. 2</dt><dd>the device in longitudinal section with a final block in the molding box.</dd></dl>

In Fig. 1, 2, the device consists of a molding box 1 for the preparation consists of a Composite block 2 (Fig. 2) with a square cross-section. The flask 1 is limited by a bottom 3 and mold walls 4, 5th is above the molding box 1 into it wheeled, hydraulically operable and not represented by a Control unit controllable punch 6 disposed. His pressing surface 7 corresponds in size and shape substantially to the cross section 8 of the block to be manufactured 2. Ends of the opposing mold walls 4 have a curvature 9 (Fig. 2, 3) while causing the vertically arranged, opposite one another Mold walls 5 each consist of a wall part 10, at which flaps 11 movably about a pivot axis 12 by means of hydraulic devices 13 are. Between the walls 4 and the flaps 11 each corners 14 are formed. The filling cross-section is designated 15 and the filling by 16.

In Fig. 2 of the die is 6 in the final position of the compression process and the block 2 is enclosed by the latter, the floor 3 and the mold walls 4, 5, wherein each wall member 10 and the flaps 11 are parallel to each other.

The operation or the new process with the new device is as follows:

The mold walls 4, 5 of the molding box 1 to stand at the angle α of 30 ° outwardly pivoted flaps 11 of the mold walls 5 a seal on the floor. 3 The flaps 11 are sealed at the bends. 9 With highly been run Stamp 6 will now be with binder sprayed polyurethane foam flakes an edge length of about 10 to 15 mm in the filling cross-section 15 in a predetermined amount of input. The loose fill such foam flocks has a density of about 15 kg / m³, The present in the molding box 1 Filling 16 is a block height of 0.5 m at a density of 60 kg / m³are compacted. First, the flaps 11 are inwardly in the parallel Position pivoted with the wall parts tenth Here, the increased in the Corners 14 located flakes displaced inwards and fill thereby formed Hollow spaces. Since the cross-sectional and increase in volume for the filling was known from empirical investigations, results with the achievement the parallel position of the flaps 11 with the wall parts 10 a homogeneous density over the entire cross-section 8. Now the punch 6 is raised and then the molding box 1 is pulled upward. The finished block 2 can now be removed.